Misato Fukagawa
A5089113599- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Molecular Spectroscopy and Structure
- Gamma-ray bursts and supernovae
- Space Exploration and Technology
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Spacecraft and Cryogenic Technologies
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Radio Astronomy Observations and Technology
- High-pressure geophysics and materials
- Optical Systems and Laser Technology
- Planetary Science and Exploration
- Superconducting Materials and Applications
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
- Anaerobic Digestion and Biogas Production
- Advanced Measurement and Metrology Techniques
National Astronomical Observatory of Japan
2009-2025
Osaka University
2009-2019
Nagoya University
2006-2019
Max Planck Institute for Astronomy
2019
Max Planck Society
2019
Kobe University
2009-2018
Toneyama National Hospital
2009-2012
Osaka Health Science University
2012
The University of Tokyo
2002-2009
Princeton University
2009
We present high-resolution, H-band, imaging observations, collected with Subaru/HiCIAO, of the scattered light from transitional disk around SAO 206462 (HD 135344B). Although previous sub-mm imagery suggested existence dust-depleted cavity at r~46AU, our observations reveal presence components as close 0.2" (~28AU) star. Moreover, we have discovered two small-scale spiral structures lying within 0.5" (~70AU). models for using density wave theory, and derive a aspect ratio h~0.1, which is...
We present new 1--1.25 micron (z and J band) Subaru/IRCS 2 (K VLT/NaCo data for HR 8799 a rereduction of the 3--5 MMT/Clio first presented by Hinz et al. (2010). Our yields detection fourth planet at projected separation ~ 15 AU -- "HR 8799e". also report new, albeit weak detections 8799b 1.03 microns 3.3 microns. Empirical comparisons to field brown dwarfs show that least HR8799c, possibly 8799d, have near-to-mid IR colors/magnitudes significantly discrepant from L/T dwarf sequence....
We report on the properties of pre-main-sequence objects in Taurus molecular clouds as observed seven mid- and far-infrared bands with Spitzer Space Telescope. There are 215 previously identified members star-forming region our ∼44 deg2 map; these exhibit a range colors that we take to define young stars still surrounded by circumstellar dust (noting ∼20% bona fide no detectable excesses). looked for new survey field similar properties, aided extensive optical, X-ray, ultraviolet imaging,...
We present a new method to constrain the grain size in protoplanetary disks with polarization observations at millimeter wavelengths. If dust grains are grown comparable wavelengths, expected have large scattering opacity and thus continuum emission is be polarized due self-scattering. perform 3D radiative transfer calculations estimate degree for having radial Gaussian-like surface density distributions, which been recently discovered. The maximum set $100 {\rm~\mu m}$ observing wavelength...
We report high-resolution 1.6 $\micron$ polarized intensity ($PI$) images of the circumstellar disk around Herbig Ae star AB Aur at a radial distance 22 AU ($0."15$) up to 554 (3.$"$85), which have been obtained by high-contrast instrument HiCIAO with dual-beam polarimetry. revealed complicated and asymmetrical structures in inner part ($\lesssim$140 AU) disk, while confirming previously reported outer ($r$ $\gtrsim$200 spiral structure. imaged double ring structure $\sim$40 $\sim$100...
We present the first near-IR scattered light detection of transitional disk associated with Herbig Ae star MWC 758 using data obtained as part Strategic Exploration Exoplanets and Disks Subaru, 1.1 micron HST/NICMOS data. While sub-millimeter studies suggested there is a dust-depleted cavity r=0.35, we find close 0.1 (20-28 AU) from star, no visible at H, K', or Ks. two small-scaled spiral structures which asymmetrically shadow outer disk. model one spirals density wave theory, derive aspect...
We present a near-infrared image of the Herbig Ae star AB Aur obtained with Coronagraphic Imager Adaptive Optics mounted on Subaru Telescope. The shows circumstellar emission extending out to radius r = 580 AU, double spiral structure detected at 200-450 AU. surface brightness decreases as r-3.0±0.1, steeper than radial profile optical possibly affected by scattered light from envelope surrounding Aur. This result, together size infrared similar that 13CO (J 1-0) disk, suggests is indeed...
We present the direct imaging discovery of an extrasolar planet, or possible low-mass brown dwarf, at a projected separation 55 +/- 2 AU (1.058 0.007 arcsec) from B9-type star Kappa And. The planet was detected with Subaru/HiCIAO during SEEDS survey, and confirmed as bound companion via common proper motion measurements. Observed near-infrared magnitudes J = 16.3 0.3, H 15.2 0.2, Ks 14.6 0.4, L' 13.12 0.09 indicate temperature ~1700 K. galactic kinematics host are consistent membership in...
Debris discs are a consequence of the planet formation process and constitute fingerprints planetesimal systems. Their solar system's counterparts asteroid Edgeworth-Kuiper belts. The DUNES survey aims at detecting extra-solar analogues to belt around solar-type stars, putting in this way system into context. allows us address some questions related prevalence properties We used {\it Herschel}/PACS observe sample nearby FGK stars. Data 100 160 $\mu$m were obtained, complemented cases with...
We present high resolution H-band polarized intensity (PI; FWHM = 0."1: 14 AU) and L'-band imaging data (FWHM 0."11: 15 of the circumstellar disk around weak-lined T Tauri star PDS 70 in Centaurus at a radial distance 28 AU (0."2) up to 210 (1."5). In both images, giant inner gap is clearly resolved for first time, radius ~70 AU. Our show that geometric center shifts by ~6 toward minor axis. confirm brown dwarf companion candidate north background based on its proper motion. As result SED...
We present Subaru/IRCS J-band data for Fomalhaut and a (re)reduction of archival 2004–2006 HST/ACS first presented by Kalas et al. confirm the existence candidate exoplanet, b, in both 2004 2006 F606W sets at high signal-to-noise ratio. Additionally, we detection F814W new F435W. b's space motion may be consistent with it being an apsidally aligned, non-debris ring-crossing orbit, although astrometry is required firmer conclusions. cannot that b exhibits 0.7–0.8 mag variability cited as...
We combine the results from several multiplicity surveys of pre-main-sequence stars located in four nearby star-forming regions with Spitzer data three different Legacy Projects. This allows us to construct a sample 349 targets, including 125 binaries, which we use investigate effect companions on evolution circumstellar disks. find that distribution projected separations systems excesses is significantly (P∼ 2.4e-5, according K–S test for binaries less than 400 AU) lacking evidence disk. As...
Abstract We report on ALMA observations of the dust continuum, and $^{13}\textrm {CO} (J=3-2), \textrm {and} {C}^{18} \textrm{O} (J=3-2)$ line emission toward a gapped protoplanetary disk around HD 142527. The outer horseshoe-shaped shows strong azimuthal asymmetry in continuum with ratio $\sim 30$ to 1 at 336 GHz between northern peak southwestern minimum. In addition, maximum brightness temperature 24K its area is exceptionally high 160 au from star. To evaluate surface density this...
We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet β Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, precision measurements. While Pic b's near-IR colors mimic those a standard, cloudy early-to-mid L dwarf, it is overluminous mid-infrared compared field L/T dwarf sequence. Few substellar/planet-mass objects—i.e., κ And 1RXJ 1609B—match JHKsL' photometry its...
We present the polarization observations toward circumstellar disk around HD 142527 by using Atacama Large Millimeter/submillimeter Array (ALMA) at frequency of 343 GHz. The beam size is $0.51 " \times 0.44 "$, which corresponds to spatial resolution $\sim$ 71 $\times$ 62 AU. polarized intensity displays a ring-like structure with peak located on east side fraction $P= 3.26 \pm 0.02$ %, different from continuum emission northeast region. significantly weaker where 0.220 0.010$ %. vectors are...
Two studies utilizing sparse aperture masking (SAM) interferometry and $H_{\rm \alpha}$ differential imaging have reported multiple jovian companions around the young solar-mass star, LkCa 15 (LkCa bcd): first claimed direct detection of infant, newly-formed planets ("protoplanets"). We present new near-infrared imaging/spectroscopy from SCExAO system coupled with CHARIS integral field spectrograph multi-epoch thermal infrared Keck/NIRC2 at high Strehl ratios. These data provide look same...
In recent years, the disk populations in a number of young star-forming regions have been surveyed with ALMA. Understanding properties and their correlation those central star is critical to understand planet formation. particular, decrease average measured dust mass age region has observed. We conducted high-sensitivity continuum ALMA observations 43 Class II stellar objects CrA at 1.3 mm (230 GHz). The typical spatial resolution 0.3". fluxes are used estimate masses disks, survival...
We discovered a unique morphology in disk around the Herbig Ae star HD 142527 by near-infrared (H and K bands) adaptive optics imaging observations. The almost face-on consists of two bright arcs facing one another along east-west direction (banana-split structure) spiral arm extending to north from western arc. eastern arc is located at ~100-400 AU radius star, detected ~150-490 AU. stellar position displaced center about 20 north, also inner hole. show an asymmetry their size brightness;...
We present H- and Ks-band imaging data resolving the gap in transitional disk around LkCa 15, revealing surrounding nebulosity. detect sharp elliptical contours delimiting nebulosity on inside as well outside, consistent with shape, size, ellipticity, orientation of starlight reflected from far-side wall, whereas near-side wall is shielded view by disk's optically thick bulk. note that forward scattering surface could provide an alternate interpretation In either case, this discovery...
We present new $L^\prime$ (3.8 $μm$) and Br-$α$ (4.05 data reprocessed archival for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo Subaru/IRCS. detect all four planets in each dataset at a moderate to high signal-to-noise (SNR $\gtrsim$ 6-15). fail identify fifth planet, "HR f", $r$ $
The disk around the Herbig Ae star HD\,169142 was imaged and resolved at 18.8 24.5\,$\mu$m using Subaru/COMICS. We interpret observations a 2D radiative transfer model find evidence for presence of large gap. MIR images trace dust that emits onset strong rise in spectral energy distribution (SED) 20\,$\mu$m, therefore are very sensitive to location characteristics inner wall outer its dust. determine be 23$^{+3}_{-5}$\,AU from star. An extra component hot must exist close hydrostatic...
We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around star 2MASS J16042165-2130284 obtained with HiCIAO mounted on Subaru 8.2 m telescope. present our $H$-band data, which clearly exhibits a resolved, face-on large inner hole for first time at infrared wavelengths. detect centrosymmetric polarization pattern in material as has been observed other disks. Elliptical fitting gives semimajor axis, semiminor and position angle (P.A.) 63...
Subaru-HiCIAO observations on FU Orionis objects revealed asymmetric structures 10 2 to 3 AU scales of circumstellar disks and envelopes.